Tension-indicating device for sewing-machines.



I. 0. ADAMS.

TENSION INDICATING DEVICE FOR SEWING MACHINES. APPLICATION FILED APFLZQ' 1918.

Patented Dec. 31, 1918.

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, UNITED s'rnrns PATENT caries.

IRA ocrro ADAMS, or nUnAn'r, IOWA.

TENSION-INDICATING DEVICE FOR SEWING-MACHINES. I

Specification of Letters Patent.

Patented Dec. 31, 1918.

Application filed Apri129, 1918. Serial No. 231,469.

. To all whom it may concern:

Be it known that I, IRA O. ADAMS, a citizen of the United States, residing at Durant, in the county of Cedar and State of Iowa, have invented new and useful. Improvements in Tension-Indicating Devices for Sewing-Machines, of which the following is a specification.

' breaks.

This invention relates to indicating de-- vices and has for its object the provision of a device adapted primarily for use in connection with" domestic sewing machines, whereby to provide means for ascertaining whether or not the tension upon the upper andlower threads is equal.

It is well known to users of sewing machines that unless the tension upon the upper thread is the same as the tension upon the lower thread, the stitches will either pucker may be operated without any degree of mechanical skill, which will be inexpensive to manufacture, and which will fulfil its indicating function in a thoroughly efficient and reliable manner.

With these and other objects and advantages in view, the invention consists in the novel construction and arrangement to be hereinafter more fully described and claimed and illustrated in the accompanying drawing, in which- Figure 1 is an elevation of the device in use and engaged by the upper and lower threads of a sewing machine.

Fig; 2 is a longitudinal sectional view therethrough, and,

Fig. 3 is a detail view illustrating a slightly modified form.

Fig. 4 is a fragmentary perspective view illustrating a slight modification of the thread engaging means.

Referring more particularly to the drawing, the letter A designates the upper thread coming from the needle of a sewing machine. and B designates the lower thread coming from the bobbin. Certain parts of the sewing machine are shown in more or less-diagrammatic outline for better illustrating the application of my invention.

' My device comprises a body 5 stamped or otherwise formed preferably from sheetmetal and including a main relatively large portion 6 having extending centrally from the rear edge thereof, an integral handle 7 and having extending centrally of its forward edge a reduced extension 8 apertured as shown at 9. This constitutes the relatively fixed portion of the device.

Disposed upon the relatively large portion 6 of the supporting plate and spaced therefrom by a suitablewasher 10, is a mov-' able member 11 formed substantially crescent-shaped with the forwardly projecting horns-12 and provided with an integrally formed pointer 13. The movable member 11 is provided with an aperture 14 registering with the aperture 9 of the extension 8,

provided for the passage of a securing bolt 15 having its threaded end provided with a nut 16. These partsv are so arranged that the .movable member 11 is freely revoluble upon the extension 8. When the member 11 is moved (upon the pivoting bolt 15 the polnt of the pointer 13 will move in the arc of a circle and in order that the degree of .the inclination of the axis of the member 11 in relation to the axis of the supporting member 5 may be determined, I provide upon the plate portion 6, a number of spaced arcuate lines 17 struck from the pivot point 15 as a center andintersected by radial di vision lines 18.

As shown in Fig. 1, the horns 12 are provided with angularly extending heads 19 disposed ata very acute angle to the outer edges of the horns, whereby a thread receiving notch I is formed. I preferably, though not necessarily, further provide the horns 12 with grooves 20 extending diagonally across the notches therein, these grooves serving as thread guiding and retaining means.

Instead of providing the well defined notches shown in the preferred form, I may, as shown in Fig. 3, form the ends of the horns with reduced necks 21 terminating in enlarged heads 22, omitting the grooves, or not, if desired. In this form the threads would be retained upon the horns by tying the horns to the vertices of 1 them or looping them around the necks 21.

In use, the upper and lower threads A and B are pulled a sufficient distance away from the needle and presser foot of the sewing machine and are then caught in the grooves 20 and notches and, if necessary, looped around the horns, so that they will not slip. The operator then grasps the device by the handle 7 and exerts a gentle pull thereon in a plane intermediate the points of emergence of the threads A and B from the upper and lower guides, respec tively. If the tension on both threads is the same, there will be no movement of the member 11 and the pointer 13 will have its point disposed in alinement with the central graduations on the plate 6. If, however, the tension on one thread is greater than the tension on the other, the member 11 will swing upon its pivot 15, the degree of movement depending upon the difference in tension, and the pointer 13 will be correspondingly moved. If the tension is thus found to be unequal, the independent adjusting devices are adjusted in the customary manner until a pull upon the handle 7 will result in no angular movement of the member 11. I

From the foregoing description and a study of the drawing it will be apparent that I have thus provided an extremely simple and eflicient device whereby any, even slight, difference between the tension on the upper and lower-threads may be readily detected so that proper adjustment may be made.

It will of course be understood that the embodiment of my invention shown and described is merely illustrative, as I reserve the right to make such changes in the form, construction and arrangement of parts as will not depart from the spirit of the invention nor the scope of the subjoined claims.

- tions and ha'vin Having thus described my invention what is claimed is:

1. A device of the character described comprising a relatively stationary plate provided With graduations, a relatively movable plate disposed fiat upon and pivotally connected with said relatively stationary plate, an indicator hand formed on said movable plate and movable over said graduation, a handle on said relatively stationary plate, and laterally extending arms formed on said movable plate and provided with thread engaging notches. I

2. A device of the character described comprising a relatively stationary plate provided with graduations' and havinga handle thereon, a movable member disposed flat upon and pivotally connected with said relatively stationary plate and formed as a plate having an indicator hand formed integrally thereon and traveling over said graduations, said movable platebeing provided at opposite sides of'its pivot with thread engaging notches.

3. A device of the character described comprising a plate provided with graduaa handle formed thereon. a movable mem erpivoted on said plate and having an indicator hand movable over said plate and cooperatin with the graduations thereon, said mova 1e member being provided with notches on either side of its. pivot for engagement' of a number of threads under individual tension, a difference between the tensions resulting in pivotal movement vof said movable member upon rectilinear pull upon said handle.

In testimony whereof I afiix my signature. i

IRA OTTO ADAMS. 

